California Bioresources Alliance*

Organic materials—including food waste, yard trimmings, soiled paper, and wood waste—are often forgotten when considering the three “Rs” of reducing, reusing, and recycling. However, organic materials are the largest component of our solid waste stream, composing two-thirds of the solid waste stream.

In addition, organic materials can be turned into valuable products like compost and mulch. Compost and mulch are very rich soil amendments that help in food production, erosion control and clean water runoff.

Another means of recycling organic materials that is growing in popularity is the anaerobic digestion of food waste. In the absence of oxygen, food waste is broken down and methane is produced that can be used for electricity. This is especially valuable in urban areas that do not have a lot of land for compost facilities.

In recent years the recycling of organic materials has become even more important due to the reduction in greenhouse gas emissions it offers. When organic materials are sent to a landfill, they release methane, a greenhouse gas 23 times more potent than Carbon Dioxide. In comparison, when these organic materials are composted or anaerobically digested, fewer emissions are released and the emissions are typically Volatile Organic Carbon (VOC’s) that are less potent than methane. In addition, composting is a significant greenhouse gas emission mitigation measure because it results in greater carbon sequestration in crop biomass, a decrease in the need for GHG-releasing fertilizers and pesticides, and a decline in energy-intensive irrigation.